Pests and Diseases: Tomato Hornworm


With all of the warm weather we are having, it makes me think for a moment that I can walk outside and pick a fresh tomato off of the vine. But alas, it’s still January. When the warm weather does arrive, the pests and diseases that want to attack my beloved tomatoes will be lurking, waiting for the perfect opportunity to strike. Today, I want to look at the tomato hornworm so that we can all be prepared for how to deal with this vegetable villain.

tomato hornworm

Tomato hornworm is obviously a fan of tomatoes but they also enjoy other members of the Solanum genus such as Jimson Weed, nightshade and horsenettle. Keep that in mind if you have trouble with tomato hornworm…eliminating the other hosts can help in controlling them on your veggies. They also can be found munching on your peppers and eggplants so beware. These pests could pass for a chameleon relative as there ability to disguise themselves is uncanny…and that’s why they are capable of defoliating large portions of young tomatoes in the blink of an eye.

Tomato hornworm is 3.5″ to 4″ long as a mature caterpillar which is pretty big when you think about it. I’m not a fraidey cat but I must admit that I don’t enjoy squishing them because they are so large. Now give me an aphid and I’m a beast…I can squish them by the hundreds if need be! You really do need to dispose of them instead of tossing them aside and hoping that the birds pick them off. The mature caterpillar will drop off of the plant and then pupate into a moth if you leave them to their own devices.

Tomato hornworm eggs are laid on both the upper and lower sides of the leaves in late spring. If there is a saving grace here it is that they are deposited as single eggs, instead of in large groups. The moth that lays the eggs are known as hummingbird moths or sphinxs. Not all hummingbird moths evolve from tomato hornworms for the record…just some of them.


By far and away the best control method for tomato hornworms is hand picking them. You can either squish them, put them in a bucket of soapy water or feed them to your chickens if you are lucky enough to have them. But as we discussed above, don’t just toss them and hope that nature takes care of them. More than likely, nature will prevail but it will mean that you have a larger population of tomato hornworms instead of the robin consuming them for lunch. The good news is that with regular scouting of your tomatoes, you will be able to quickly notice when the tomato hornworm has invaded your garden. Let me know if you’ve had problems with tomato hornworms in your garden and what you’ve done to remedy the situation. Leave me a comment below or e-mail me at Happy gardening!

January 31, 2012Permalink Leave a comment

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